sh.enableSharding()

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Definition

Syntax
Behavior
Example

Definition

sh.enableSharding(database, primaryShard): Enables sharding on the specified database. Once you enabled sharding for a database, you can use sh.shardCollection() to shard collections in that database. The mongosh method sh.enableSharding() wraps the enableSharding command.
Important
mongosh Method
This page documents a mongosh method. This is not the documentation for database commands or language-specific drivers, such as Node.js.
For the database command, see the enableSharding command.
For MongoDB API drivers, refer to the language-specific MongoDB driver documentation.

Syntax

The sh.enableSharding() has the following form:

sh.enableSharding(
   <database>,
   <primary shard>  // Optional.
)

Parameter

The sh.enableSharding() method takes the following parameter:

Parameter	Type	Description
database	String	The database for which you wish to enable sharding.
primaryShard	String	Optional. The primary shard for the database; the primary shard contains the unsharded collection for this database. In general, rather than explicitly specifying the primary shard, it is recommended to let the balancer select the primary shard instead. Warning Tip In general, you should not need to specify the primary shard. Allow the balancer to select the primary shard instead.

Behavior

Write Concern

mongos uses "majority" for the enableSharding command and its helper sh.enableSharding().

Primary Shard

In general, you should not need to specify the primaryShard in the command. Instead, allow the balancer to select the primary shard.

However, if you do specify the primary shard for a database and the database is already enabled for sharding with a different primary shard, the operation returns an error and the primary shard for the database remains as before. To change the primary shard for a database, use the movePrimary command instead.

Example

The following example, run from a mongos, enables sharding for the test database:

sh.enableSharding("test")

To verify, run sh.status().

Definition

Important

mongosh Method